<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>圆球游戏</title>
    <script src="https://unpkg.com/vue@3/dist/vue.global.js"></script>
    <style>
        body {
            margin: 0;
            padding: 0;
        }
        .container {
            position: relative;
            margin: 0 auto;
            width: 440px;
            height: 440px;
            background-color: blanchedalmond;
        }
        .ball {
            position:absolute;
            width: 30px;
            height: 30px;
            left:0px;
            top:0px;
            background-color:orange;
            border-radius: 30px;
        }
        .board {
            position:absolute;
            left: 0;
            bottom: 0;
            height: 10px;
            width: 80px;
            border-radius: 5px;
            background-color: red;
        }
    </style>
</head>
<body>
    <div id="Application">
        <!-- 游戏区域 -->
        <div class="container">
            <!-- 底部挡板 -->
            <div class="board" :style="{left: boardX + 'px'}"></div>
            <!-- 弹球 -->
            <div class="ball" :style="{left: ballX+'px', top: ballY+'px'}"></div>
            <!-- 游戏结束提示 -->
            <h1 v-if="fail" style="text-align: center;">游戏失败</h1>
        </div>
    </div>
    <script>
        const App = {
            data() {
               return {
                    // 控制挡板位置
                    boardX:0,
                    // 控制弹球位置
                    ballX:0,
                    ballY:0,
                    // 控制弹球移动速度
                    rateX:0.1,
                    rateY:0.1,
                    // 控制结束游戏提示的展示
                    fail:false
               }
            },
            // 组件生命周期函数，组件加载时会调用
            mounted() {
                // 添加键盘事件
                this.enterKeyup();
                // 随机弹球的运动速度和方向
                this.rateX = (Math.random() + 0.1)
                this.rateY = (Math.random() + 0.1)
                // 开启计数器，控制弹球移动
                this.timer = setInterval(()=>{
                    // 到达右侧边缘进行反弹
                    if (this.ballX + this.rateX  >= 440 - 30) {
                        this.rateX *= -1
                    }
                    // 到达左侧边缘进行反弹
                    if (this.ballX + this.rateX <= 0) {
                        this.rateX *= -1
                    }
                    // 到达上侧边缘进行反弹
                    if (this.ballY + this.rateY <= 0) {
                        this.rateY *= -1
                    }
                    this.ballX += this.rateX
                    this.ballY += this.rateY
                    // 失败判定
                    if (this.ballY >= 440 - 30 - 10) {
                        // 挡板接住了弹球，进行反弹
                        if (this.boardX <= this.ballX + 30 && this.boardX + 80 >= this.ballX) {
                            this.rateY *= -1
                        } else {
                        // 没有接住弹球，游戏结束
                            clearInterval(this.timer)
                            this.fail = true
                        }
                    }
                },2)
            },
            methods: {
                // 控制挡板移动
                keydown(event){
                    if (event.key == "ArrowLeft") {
                        if (this.boardX  > 10) {
                            this.boardX -= 20
                        } 
                    } else if (event.key == "ArrowRight") {
                        if (this.boardX  < 440 - 80) {
                            this.boardX += 20
                        } 
                    }
                },
                enterKeyup() {
                    document.addEventListener("keydown", this.keydown);
                }
            }
        }
        Vue.createApp(App).mount("#Application") 
    </script>
</body>
</html>